Others of notable mention...

Edmodo

• Like a facebook page for your class.
• Each pupil has their own login.
• 100% safe and secure.
• Free.
• Ability to share links; video; pics; share info; upload work; comment on others’ work...

Screencast-o-matic

• Add audio to your power points.
• Essentially create a movie out of them, moving slides at your own ace and adding audio to give further explanations (as you would in the classroom).
• Can be excellent for revision.
• Pupils could also use it to add further explanations from your powerpoint notes.

ClassDojo

• Have literally just come across it! I have therefore not used it, but can see the potential in it. It is essentially a real-time classroom management interface, where you can reward pupils immediately. I don't have enough time to look fully into it, but feel free to and let me know any feedback! Click the link above for more information.